In the context of the NIOPLEX project a workshop on data assimilation was held at the Technische Universität Berlin from 26th to 27th February 2015. About 20 participants attended the workshop and made it to a valuable and pleasant event. In addition to the three invited speakers also NIOPLEX members (from work package 2) contributed to the workshop. The workshop provided both the transfer of the knowledge and expertise generated in the project to beyond the consortium as well as new inspiration for all participants. The first day closed with a workshop diner provinding the opportunity to socialise in academic and personal sense. Friday morning was used for bilateral discussions of the collaborating partners within the WP2.